Yajirobe Ueno leads the Taito Tribe, a Neo-Tokyo faction based in Taitō ward known for championing art and romance over turf wars. He built the tribe through sheer reputation, drawing in rough characters like the ace Hanafuda Sakura. Despite commanding this group, he rarely fights, leaving his true combat strength shrouded in mystery.

Standing 185 cm tall and weighing 72 kg, he possesses petrol-blue hair and matching eyes. His capabilities include superhuman physical traits, martial arts skill, and mastery of his signature baseball bat. He reflects physical projectiles, exhibits superhuman athleticism and acrobatics—effortlessly scaling buildings by leaping off walls—and operates at a small building level in attack potency, striking strength, and durability, scaling to those who damaged Minato Tower's peak. His hypersonic+ speed allows reactions to Mach 10 projectiles, supported by above-average lifting strength and stamina enabling runs of hundreds of meters. His standard baseball bat and ball extend his effective range to tens of metres.

Assessments suggest ESTJ and Enneagram 9w1, though his present-focused demeanor, emotional detachment, and hands-on preference hint at ISTP traits. He actively avoids conflict and confrontation, displaying disinterest in team dynamics or tournaments beyond personal gain, encapsulated in his defining quote: "I don’t care about the team or the tournament, I’m just here to eat." While empathetic to others' perspectives, his passive leadership can manifest as indecisiveness. This passivity defines his tribe's tactic: exploiting opponents' underestimations over direct aggression.